Comfort-Aire GDD95A Downflow Furnaces - Manual (Page 6)

6
ABOUT THE FURNACE
INTRODUCTION
Congratulations on the purchase on your new furnace!
With our dedication to quality, superior reliability, and
outstanding warranty, we know you will be pleased with
this new appliance. This furnace has been designed and
built to provide many years of safe and dependable home
comfort, providing it is properly installed and regular
maintenance has been performed. Improper use or
insufficient maintenance can shorten the life of the furnace
and result in serious personal injury or property damage.
Please read this manual thoroughly and familiarize yourself
with the safety, operation and maintenance procedures for
this furnace. DO NOT DESTROY THIS MANUAL. KEEP
IN A SAFE PLACE FOR FUTURE REFERENCE.
Your furnace is designed to fulfill the requirements of being
classified as either a Category I or Category IV furnace.
These classifications are related to the furnace’s Annual
Fuel Utilization Efficiency (AFUE) rating, the percentage
of fuel that is converted into usable heating energy.
The furnace components shown on pages 7 - 9 will help
to identify and locate various parts of the furnace. The
component you need to familiarize yourself with is the
gas valve. You will use this to turn the furnace on and off.
There are no user serviceable parts. All repairs must
be performed by a licensed HVAC technician.
Category I (Non-Condensing) Furnaces
These furnaces typically have an AFUE rating of about
80% and may be vented through a properly designed metal
vent or masonry chimney. This venting system needs to
be primarily vertical, so that the hot combustion products
will develop a natural upwards draft action.
Category IV (Condensing) Furnaces
Category IV furnaces typically have an AFUE rating over
90% and are mainly vented through plastic PVC pipe.
These furnaces also produce liquid condensate which
is slightly acidic. The vent pipe must be sloped upwards
away from the furnace to properly drain the condensate
back to the condensate disposal system.
• Condensing type furnaces require condensate drain
lines to be properly installed by the installer. Depending
on your configuration, the drain lines may be routed
out the left or right sides of the furnace. These drain
lines must maintain a downward slope to ensure proper
condensate drainage.
• Condensate must flow freely during furnace operation.
The homeowner must make sure the condensate drain
lines do not become blocked, pinched or crushed.
• If the furnace is installed in an area where temperatures
fall below freezing, special precautions must be made
for insulating condensate drain lines that drain to the
outdoors.
If condensate freezes in the lines, this will
cause the condensate drain switch to shut down
the furnace. Only a licensed HVAC technician can
reset this switch.
FILTER
WARNING:
Never operate the furnace without a filter in
place. Accumulating dust in the return air can
build up on internal components, resulting
in loss of efficiency, equipment damage, and
possible fire.
• Air filter(s) are not supplied with the furnace as
shipped from the factory. The installer must provide
a high velocity filter and rack for a filter in the return air
duct adjacent to the furnace, or in a return air grill to
the furnace.
• The furnace should always have a clean filter located
either at the air return on the furnace or in an air return
register. If the filter becomes dirty, it should be cleaned
or replaced.
• New or newly renovated homes may require more
frequent changing until the construction dust has
minimized. Filters designed to remove smaller particles
such as pollen, may require additional maintenance.
• Always reinstall the doors on the furnace after servicing
or cleaning/changing the filters. Do not operate the
furnace without all doors and covers in place.
THERMOSTAT
This family of furnaces includes single stage and two-stage
capabilities. These different capabilities require different
thermostats to reach their best performance.
• Single stage furnaces (GUH80A, GDD80A, GUH92A,
GDD92A, GUH95A, & GDD95A models) should be
controlled by a conventional single stage thermostat.
• Two-stage furnaces (GUH95T models) will perform
best with a conventional two - stage thermostat.
NOTE: It is possible to control two-stage furnaces with
a single stage thermostat. Consult with your installer
about which type is best for your installation. Both
thermostats are commonly available at your local
building supply store.
FURNACE LOCATION
If a furnace is installed in relatively small utility room or
closet, the installation needs openings in the walls or door
to let combustion air in. Make sure that these openings
remain unobstructed. Do not modify these openings in
any way without consulting a licensed HVAC technician.